耐力训练诱导AMPK对小鼠骨骼肌PP38-磷酸化MEF2影响

发布时间：2018-06-02 17:59

本文选题：腺苷酸活化蛋白激酶α2 + 丝裂原活化蛋白激酶p38　；参考：《北京体育大学》2012年硕士论文

【摘要】：研究发现AMPK可以激活GLUT4的表达,但是AMPK调节GLUT4表达的具体机制尚不清楚。多项研究表明MEF2是GLUT4转录过程的必需因子。MAPK亚家族成员-P38MAPK可通过磷酸化途径活化MEF2,增强其转录活性。同时AMPK可以激活下游的p38转化为pp38。研究目的：本文以AMPK α2转基因小鼠,AMPK α2基因敲除小鼠和野生小鼠为研究对象,探讨耐力训练诱导AMPK对骨骼肌p38、pp38及核内P-MEF2A蛋白表达的影响。研究方法：C5BL/6J野生鼠、AMPK α2转基因和AMPK α2基因敲除小鼠各20只,每种小鼠按体重随机分为安静对照组和耐力训练组,每组10只。对照组小鼠不施加运动负荷,安静状态下笼养,耐力训练组小鼠训练方案设计为0坡度跑台运动,速度为12m/min,每天训练一个小时,每周六天,持续四周。训练组小鼠最后一次训练结束后12小时颈椎脱臼法处死,取双侧股四头肌肉。应用Western blot法测定p38、pp38和核内p-MEF2A蛋白表达。研究结果：1)与安静对照组相比,四周耐力训练后AMPK α2三种不同基因型小鼠骨骼肌pp38蛋白表达均显著提高,并且AMPK α2转基因鼠与野生鼠相比,p38和pp38蛋白表达增加显著,AMPK α2基因敲除鼠pp38蛋白表达虽然低于野生鼠,但没有显著性差异；2)与安静对照相比,AMPK α2三种基因型鼠骨骼肌核内P-MEF2A蛋白表达均显著增加,并旦AMPK α2转基因鼠与野生鼠相比,p-MEF2A蛋白表达显著增加,而AMPK α2基因敲除小鼠P-MEF2A与野生鼠相比没有显著差异；3)42只小鼠骨骼肌内pp38与细胞核内P-MEF2A表达含量呈显著正相关(R=0.69,P0.05)。研究结论：耐力训练对AMPK α2三种不同基因型小鼠骨骼肌内p38蛋白表达影响不大,但可以显著促进p38和MEF2A的激活。AMPK α2可能不是唯一激活p38和MEF2A的途径。pp38与MEF2A磷酸化促进MEF2转录活性密切相关。
[Abstract]:It was found that AMPK could activate the expression of GLUT4, but the mechanism of AMPK regulating GLUT4 expression was unclear. Several studies have shown that MEF2 is an essential factor in GLUT4 transcription. MAPK subfamily member -P38 MAPK can activate MEF2 through phosphorylation pathway and enhance its transcription activity. AMPK also activates downstream conversion of p38 to p 38. Objective: to investigate the effects of endurance training (AMPK) on the expression of p38 pp38 and P-MEF2A protein in skeletal muscle of AMPK 伪 2 transgenic mice and wild mice. Methods 20 AMPK 伪 2 transgenic mice and 20 AMPK 伪 2 knockout mice were randomly divided into quiet control group and endurance training group according to their body weight. The control group did not exert exercise load and was kept in captivity in quiet state. The training scheme of endurance training group was designed as 0 slope running platform exercise with a speed of 12 m / min, training for one hour per day, six days a week for four weeks. The mice in the training group were killed 12 hours after the last training, and bilateral quadriceps femoris muscles were taken. Western blot assay was used to detect the expression of p38 p 38 and p-MEF2A protein in nucleus. Results: compared with the quiet control group, the expression of pp38 protein in skeletal muscle of three different genotypes of AMPK 伪 2 was significantly increased after four-week endurance training. Moreover, the expression of p38 and pp38 protein in AMPK 伪 2 transgenic mice was significantly higher than that in wild mice, although the expression of pp38 protein in AMPK 伪 2 knockout mice was lower than that in wild mice. The expression of P-MEF2A protein in skeletal muscle nuclei of three genotypes of AMPK 伪 2 was significantly increased, and the expression of p-MEF2A protein in AMPK 伪 2 transgenic mice was significantly higher than that in wild mice. However, there was no significant difference between P-MEF2A of AMPK 伪 2 knockout mice and that of wild mice. There was a significant positive correlation between the expression of pp38 in skeletal muscle and the expression of P-MEF2A in nucleus of 342 mice. Conclusion: endurance training has little effect on the expression of p38 protein in skeletal muscle of three different genotypes of AMPK 伪 2 mice. However, the activation of p38 and MEF2A. AMPK 伪 2 may not be the only pathway to activate p38 and MEF2A. Pp38 is closely related to the phosphorylation of MEF2A to promote the transcriptional activity of MEF2.
【学位授予单位】：北京体育大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R87

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